Mumbai, May 12 -- Markets slumped on Monday after Prime Minister Narendra Modi urged Indians to cut fuel consumption, avoid buying gold for a year, and limit foreign travel, amid rising pressure on the rupee and on India's import bill due to supply constraints triggered by the West Asia conflict. Investors interpreted the remarks as a signal that the government may be preparing for tougher measures, including possible fuel price hikes or steps to curb imports. On Monday, the Nifty 50 and the Sensex marked their steepest single-day fall since 30 March, slumping 1.49% and 1.7%, respectively. The Prime Minister's remarks triggered a broad selloff across sectors seen as vulnerable to potential curbs or price increases, with shares of oil marketing companies, jewellers, airlines and hotels falling sharply. Nifty 50's biggest losers included jewellery maker Titan and airline operator IndiGo, which fell 6.85% and 5.73%, respectively. Oil marketing companies Indian Oil Corp., Bharat Petroleum Corp. and Hindustan Petroleum Corp. also declined sharply. Reliance Industries Ltd (RIL)-India's biggest private refiner and the heaviest-weighted stock on the Nifty 50-fell 3.48%. Other index heavyweights also dragged the benchmarks lower, with Bharti Airtel's stock falling 3.79% and State Bank of India, 4.36%....